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Eico 470 scope
DanRogers
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Joined: Oct 2014
City: Montreal, QC, CA
#1

10-11-2014, 10:47 AM
Hello all,
I'm trying to find the schematic for the Eico 470 oscilloscope, if anyone would be kind enough. The unit I'm restoring has a burn out power supply. I believe this model to be similar to the 425 version which also uses a 5Y3 as the high voltage rectifier.
Regards,
Daniel
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Radioroslyn
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City: Roslyn Pa
#2

10-12-2014, 12:45 PM
Hi Dan and welcome to the Phorum!
I can get you a copy of the 425 and the 460 but don't have one for the 470. What voltages are you missing?? Check with the rectifiers removed!
Terry
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DanRogers
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City: Montreal, QC, CA
#3

10-12-2014, 03:13 PM
Hello Terry,
Thanks for the reply.
I'd really like to get the diagram to verify the power transformer filament line up and the power supply section. The 425 has the same tube high voltage rectifier as mine ( the 470 ), while the 460 has an 1V2. So I think my wiring diagram ( at least for the power supply section ) is quite similar. Before I put in a replacement power transformer and power things up, I would like to make sure !

Its surprising that the 5y3 high voltage rectifier even worked as they were used probably at their very maximum voltage specification.

Regards,
Daniel
(This post was last modified: 10-12-2014, 03:44 PM by DanRogers.)
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Radioroslyn
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Posts: 7,248
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City: Roslyn Pa
#4

10-12-2014, 05:20 PM
So why not check the AC voltages on the plate or plates of the rectifiers?? Hv and lo voltage without the tube out so if there is a shorted cap down the line it don't be an issue.
Terry
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  1. The PHILCO Phorum
  2. Various and Sundry Categories
  3. Test Equipment